Apparatus for and method of polishing optical connectors

ABSTRACT

A holding member holding an optical connector is set in a rotary member such that the optical axis of the optical connector is at a predetermined inclination angle to the axis of rotation of the rotary member. An end face of the optical connector is then brought into contact with a polishing member. Then, the rotary member and polishing member are driven for rotation by drive means to polish the end face of the optical connector into an inclined convex spherical surface.

FIELD OF THE INVENTION AND RELATED ART STATEMENT

This invention relates to an apparatus for and a method of polishingoptical connectors and, more particularly, to inclined convex sphericalsurface polishing of the optical connector end face.

Optical fiber cables for optical communication are required that thedeviation of the connected ends of adjacent ones of them from theoptical axis has to be held within several μm. Accordingly, a connectoris fitted on each optical fiber cable end. The opposed optical fibercable ends are polished and elastically abuttedly connected to eachother. Particularly, ferrules are used, and their end face is machinedinto a convex spherical surface, whereby adjacent fibers can beconnected directly, thus permitting suppression of the connection lossand attenuation by reflection. Recently, in place of the prior artmethod of polishing the ferrule end face into a convex spherical shapewith respect to a perpendicular end face, a technique has beendeveloped, in which the ferrule end face is polished into an inclinedconvex spherical shape. FIG. 7 shows the prior art method of polishing.In this case, the ferrule end face is polished into an inclined convexspherical surface at an angle θ of 8° to it. This method, compared tothe perpendicular convex spherical surface polishing, permits reductionof the reflected return light from the optical fiber end face by 50% ormore. Thus, when adjacent optical fibers are connected, there is lesstransmission noise therein. This method thus is suited for connection inCATV or image transmission lines.

However, the prior art inclined polishing process has a problem that itis difficult to keep the excentricity of the radius of curvature of theconvex spherical surface within a predetermined permissible range. Thiswill be described briefly with reference to FIGS. 8(A) to 8(C). FIG.8(A) shows the shape of the connector end face before the polishing. Anoptical fiber 103 is inserted in a center bore 102 of a ferrule 101, andit is secured thereto by adhesive 104. The ferrule 101 has apredetermined end taper which is formed for facilitating the operationof connection. Then, as shown in FIG. 8(B), the end face of the ferrule101 is ground into an inclined plane surface at a predetermined angle.Since the ferrule preliminarily has the tapered end, the center positionP of the inclined plane ground surface 105 is deviated from the centerposition Q of the optical fiber 103. As is obvious from the Figure, thecenter position P is at a distance of A/2 from the edge of the inclinedplane ground surface 105 where A is the diametrical dimension of theground surface 105. This center position P is deviated from the centerposition Q of the optical fiber 103. Then, as shown in FIG. 8(C), theinclined plane ground surface 105 is polished into an inclined convexspherical surface 106. As is obvious from the Figure, the apex of theconvex spherical surface 106 coincides with the center position P of theinclined plane ground surface noted above. Thus, the convex sphericalsurface 106 has an excentricity with respect to the center position Q ofthe optical fiber. The excentricity extent reaches about 100 μm. Thepermissible excentricity of the radius of curvature is set to 50 μm, forinstance. Therefore, the excentricity of 100 μm extremely increases theconnection loss, which is a problem to be solved.

Meanwhile, in order to suppress the excentricity of the radius ofcurvature in such inclined convex spherical surface polishing,connectors having special ferrule end face shapes have been developed.For example, in the example of FIG. 7 noted before, the tapered ferruleend has a reduced diameter projection for joining. In this case, theferrule end face is provided with inclined convex spherical surfacepolishing on the projection for joining, thus precluding theexcentricity of the radius of curvature.

However, the end face of the ferrule shown in FIG. 7 is machined into avery special shape, which is quite different from the shape of a generalpurpose article as shown in FIG. 10. Adopting such a special shape isdisadvantageous in view of the price and versatility of part andtherefore can not be a practical measure of solving the problem.

OBJECT AND SUMMARY OF THE INVENTION

The invention has been intended in view of the above problems that havebeen inherent in the prior art, and its object is to provide anapparatus for and a method of polishing the optical connector end face,which permits inclined convex spherical surface polishing with a smallexcentricity of the radius of curvature compared to the general purposeconnector.

To attain the above object of the invention, there is provided anapparatus for polishing optical connectors, which comprises:

an optical connector support section including a holding member forholding an optical connector mounted therein and a rotary memberrotatable about a predetermined axis of rotation;

the holding member being disposed in the rotary member such that theoptical axis of the optical connector is at a predetermined angle to theaxis of rotation of the rotary member;

a polishing member section to be in contact with an end face of theoptical connector for polishing the end face to a predetermined shape;

first drive means for rotating the optical connector support section;and

second drive means for rotating the polishing member section.

According to the invention, there is further provided an apparatus forpolishing optical connectors, which further comprises adjusting meansfor adjusting the position of securement of the optical connector suchthat the point of the optical axis of the optical connector in the endface thereof coincides with the axis of rotation.

The adjusting means includes thread means able to cause advancement andretreat of the holding member in the optical axis direction or threadmeans able to cause movement of the holding member in a plane at rightangles to the axis of rotation.

Further, according to the invention, there is provided an apparatus forpolishing optical connectors, in which the angle of inclination of theoptical axis is 8° to 12°, or in which the polishing member sectionincludes an elastic polishing member.

Further, according to the invention, there is provided a method ofpolishing optical connectors, which comprises the steps of:

causing the optical axis of an optical connector to be at apredetermined angle to a predetermined axis of rotation and also causingthe point of the optical axis in an end face of the optical connector tocoincide with the axis of rotation; and

bringing the end face of the inclined optical connector into forcedcontact with the polishing member while causing rotation of the end faceabout the axis of rotation.

Further, in this method according to the invention, an opticalconnector, of which the point of optical axis if held to be coincidentwith the axis of rotation, is prepared in advance and then set in thepolishing apparatus.

According to the invention, the optical connector is held such that theoptical axis thereof is at an angle to the axis of rotation. Thus, theoptical connector end face is at a predetermined angle with respect tothe axis of rotation. When the optical connector is polished by rotatingit in this state, a desired inclined convex spherical surface can beobtained. Particularly, the center of the machined surface of theferrule is set such as to obtain coincidence of the optical axis pointand axis of rotation with each other. Thus, the optical connectorundergoes an oscillating motion about the axis of rotation with theoptical axis point as a support point. The apex of the inclined convexspherical surface thus obtained by the polishing, coincides with theoptical axis point, and thus the excentricity of the radius of curvatureof the convex spherical surface is substantially zero. In practice,however, a slight excentricity of the radius of curvature appears due toa positioning error, but it can be controlled to be sufficiently withinthe permissible range. Thus, according to the invention the reduction ofreflected return light is realized while maintaining very low insertionloss. The optical connector produced according to the invention is thussubject to low noise and suitably applicable to CAVT or imagetransmission channel jumper cables.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the invention willbecome more apparent upon a reading of the following detailedspecification and drawings, in which:

FIG. 1 is a fragmentary sectional view showing an essential part of afirst embodiment of the apparatus for optical connector end facepolishing according to the invention;

FIG. 2 is a schematic view for explaining a positioning operation in amethod of optical connector end face polishing according to theinvention;

FIG. 3 is a fragmentary enlarged-scale view showing the shape of anoptical connector end face machined according to the invention;

FIG. 4 is a graph showing the relation between frequency and end curveoffset;

FIG. 5 is a schematic view showing the overall structure of the firstembodiment of the optical connector end face polishing according to theinvention;

FIG. 6 is a side view, partly in section, showing an optical connectorsupport block assembled in the optical connector end face polishingapparatus shown in FIG. 4;

FIG. 7 is a schematic view showing prior art optical connectors havingbeen provided with inclined convex spherical surface polishing;

FIGS. 8(A) to 8(C) are schematic views for explaining a problem in theprior art inclined convex spherical surface polishing; and

FIG. 9 is a schematic view showing a second embodiment of the opticalconnector end face polishing apparatus according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the invention will now be described in detailwith reference to the drawings. FIG. 1 is a fragmentary sectional viewshowing an essential part of the first embodiment of the opticalconnector end face polishing apparatus according to the invention. Theillustrated optical connector end face polishing apparatus comprises anoptical connector support section 1 and a polishing member section 2.The optical connector support section 1 rotatably supports an opticalconnector 3 to be polished. The optical connector 3 comprises a ferrule4 having a central axial bore with an optical fiber 17 inserted therein.The ferrule 4 has a general shape. It has a tapered end 5 and a flange 6provided at an axially intermediate position. The polishing membersection 2, on the other hand, includes a polishing member 7 which can berotated or revolved. The end face 5 of the ferrule 4 projects from thelower surface of the optical connector support section 1 and is to beheld in contact with the polishing member 7 for its inclined convexspherical surface polishing. The polishing member 7 is capable ofelastic deformation, and when it is in forced contact with the end face5 of the ferrule 4, it is curved concave-wise, so that desired sphericalsurface polishing is obtainable. It is possible as well to make thepolishing member 4 of a hard material.

The optical connector support section 1 includes a rotary member 8 and asupport block 9. The rotary member 8 is assembled in the support block9. The rotary member 8 has a substantially cylindrical shape and isrotatable about a vertical axis 10 of rotation by a drive mechanism (notshown). A bearing (not shown) is interposed between the rotary member 8and the support block 9. A holding member 11 is screwedly assembled inthe rotary member 8. The holding member 11 holds and guides the opticalconnector 3 such that the optical axis 12 thereof is at a predeterminedinclination angle θ to the axis 10 of rotation. The optical axis 12coincides with the axis of the central bore of the ferrule 4 notedabove. The holding member 11 has a substantially cylindrical shapehaving an open end portion 11a. The ferrule 4 is held with its flange 6in contact with the open end portion 11a. The flange 6 has a notch (notshown), in which an external pin is engaged to prevent rotation of theferrule 4. The holding member 11 is assembled adjustably such that itcan be advanced and retreated in the direction of the optical axis 12.More specifically, an adjusting means is formed by a male and a femalethread 13 and 14 screwed together, the male thread 13 being formed inthe outer periphery of the holding member 11, the female thread 14 beingformed in the inner periphery 8a of the hollow rotary member 8. Theoptical connector 3 can be positioned by the adjusting means. Morespecifically, by turning the upper portion of the holding member 11, theferrule 4 can be advanced and retreated vertically along the opticalaxis 12 toward and away from the polishing member 7. The rotary member 8is formed in its end portion with a guide hole 15, in which is insertedthe ferrule 4 supported by the holding member 11. A coil spring 16 isinserted between the edge about the upper end of the guide hole 15 andthe flange 6 of the ferrule 4 and is biasing the ferrule 4 rearwardalong the optical axis 12. The holding member 11 thus can be advancedand retreated in the direction of the optical axis 12 to secure theoptical connector 3 in position such that the point P of the opticalaxis at the center of the end face 5 of the ferrule 4 is at apredetermined inclination angle θ to the axis of rotation. The opticalaxis point P represents the position, at which the center of the endface 5 of the ferrule 4 and the optical axis 12 intersect with eachother. Thus, when the optical axis point P is made coincident with theaxis 10 of rotation, the optical axis 12 and axis 10 of rotationintersect at the center of the end face 12.

A method of optical connector end face polishing according to theinvention will now be described with reference to FIG. 1. In a firststep, the optical connector 3 is set in the optical connector supportsection 1 such that its optical axis 12 is at a predetermined angle θ tothe axis 10 of rotation. More specifically, the optical connector 3 isset in the holding member 11, which is then assembled in the rotarymember 8. In a second step, the optical connector 3 is adjusted inposition by causing advancement and retreat of the holding member 11carrying it set therein in the direction of its optical axis through thescrewed coupling of the threads 13 and 14, and it is secured in positionsuch that the optical axis point P at the center of the end face 15 isin the axis 10 of rotation. In a third or last step, the opticalconnector 3 is caused to undergo oscillating rotation about the axis 10of rotation, thus performing inclined convex spherical surface polishingwith the inclined end face 5 in forced contact with the polishing member7.

Now, the above method of adjustment by causing advancement and retreatof the holding member 11 in the direction of the optical axis 12 will bedescribed with reference to FIG. 2. In this example, a microscope isused for the adjusting operation. As shown in the Figure, the supportblock 9, with the optical connector 3 set therein, is set under themicroscope such that the bottom of the rotary member 8 can be observed.In the microscope field 21, perpendicular hair lines X and Y aredisplayed. The support block 9 is set in the microscope such that thehair line intersection coincides with the axis 10 of rotation of therotary member 8. In the Figure, the axis 10 of rotation is perpendicularto the plane of paper. In the microscope field 21 is further displayed asection of the optical fiber 17 exposed in the ferrule end face. In theillustrated example, the optical axis 12 of the optical connector isinclined in the X direction with respect to the axis 10 of rotation.That is, the section of the optical fiber 17 appears at differentpositions on the line X depending on the position of the opticalconnector in the optical axis direction. In the illustrated case, threestates are shown. The small circle R on the right side of the hair lineintersection represents a case when the optical connector is retreatedin the optical axis direction. The left side small circle L represents acase when the optical connector is excessively projected in the opticalaxis direction. The central small circle C represents a case when theadjustment is completed. In this case, the center point at the end ofthe optical fiber 17 is accurately aligned to the axis 10 of rotation.In the above way, according to the invention the adjusting operation forpositioning the optical connector can be readily carried out by using amicroscope.

FIG. 3 is a schematic view showing the shape of optical connector endafter inclined convex spherical surface polishing thereof. According tothe invention, the inclined convex spherical surface 22 is obtained bypolishing carried out in such a state that the optical axis point P atthe end face 5 of the ferrule 4 is in the axis 10 of rotation. Thisinclined convex spherical surface 22 is obtained by polishing with theaxis 10 of rotation as reference and also with a predetermined radius ofcurvature. Its apex coincides with the optical axis point P. Thus, theexcentricity of the radius of curvature of the inclined convex sphericalsurface 22 can be made extremely small. For example, when the radius ofcurvature of the convex spherical surface 22 is set to 10 to 25 mm, itis possible to hold the excentricity to be sufficiently within thepermissible range of 50 μm. In addition, by adopting the inclined convexspherical surface, it is possible to ensure attenuation by reflection tobe 60 dB or above and insertion loss to be 0.5 dB or below. To this end,the inclination angle θ of the optical axis 12 is suitably set in arange of 8° to 12°.

In order to let the optical axis 12 of the optical connector 3 becoincident with the axis 10 of rotation of the rotary member 8 at theoptical axis point P on the optical connector end face 5, the abovefirst embodiment of the invention has used the adjusting means, whichcomprises the male thread 13 formed in the outer periphery of theholding member 11 and the female thread 14 formed in the inner periphery8a of the hollow rotary member 8. Specifically, in the above firstembodiment the optical connector 3 is positioned after it has been setin the rotary member 8. This arrangement, however, is by no meanslimitative. For example, it is possible to prepare a separatepositioning member while providing, on the side of the rotary member 8,a reference surface which corresponds to a positioning surface of thepositioning member. In this case, the optical connector 3 is first setin the positioning member, and the length of extension of the opticalconnector end face 5 is set with the positioning surface. Then, theoptical connector is removed from the positioning member and then set inthe rotary member such that it is in contact with the reference surfaceof the rotary member. By so doing, the optical axis 12 and the axis 10of rotation automatically coincide with each other at the optical axispoint P of the optical connector end face 5, thus making any subsequentadjustment unnecessary.

FIG. 4 is a graph showing a relationship between frequency and end curveoffset, obtained with the above polishing apparatus according to theinvention. As is seen from the Figure, the average end curve offset is30.4 μm, which is within the permissible excentricity of the radius ofcurvature of 50 μm. Thus, it will be seen that the optical fiberconnection loss is extremely reduced.

Now, an example of the overall construction of optical connector endface polishing machine will be described, in which the optical connectorsupport and polishing member sections 1 and 2 shown in FIG. 1 areassembled. This construction is assembled by using a base 31, which iscalled C type or column type and has excellent rigidity. The polishingmachine comprises an optical connector support block 1, which has aplurality of rotary members 8 each for rotatably holding an opticalconnector. The optical connector support block 1 is substantiallydisk-like in shape and carries the plurality of rotary members 8 in acircumferential uniform interval arrangement. Holding member 11, asshown in FIG. 1, is assembled in each rotary member 8 for supporting andguiding the optical connector in such an attitude that the optical axis12 is at a predetermined angle to the axis 10 of rotation. The end face5 of the optical connector that is set in the holding member 11,projects from the bottom surface la of the optical connector supportblock 1. As noted before, the holding member 11 is capable of positionadjustment by being advanced and retreated in the optical axisdirection, and it is positioned such that the optical axis point on theoptical connector end face 5 coincides with the axis 10 of rotation. Theoptical connector support block 1 includes an internal rotation drivemechanism for rotating the individual rotary members 8. Thus, theoptical connector supported in the holding member 11 undergoesoscillating rotation about the axis 10 of rotation.

A main shaft 32 is inserted in an upper portion of the base 31. Theoptical connector support block 1 is detachably mounted on the lower endof the main shaft 32. The main shaft 32 comprises an outer quill and aninner shaft member coaxial therewith. The quill is vertically movable,while the shaft member is rotatable in both directions. Atop the base31, a first drive system 33 coupled to the main shaft 32 is mounted. Thefirst drive system 33 includes a feed mechanism, which can move theoptical connector support block 1 in the axial direction via the quillof the main shaft 32, and a rotation mechanism, which can drive eachrotary member 8 in the block 1 via the shaft member of the main shaft32. The base 1 has a handle 34 mounted on its side wall for moving themain shaft 32 in the vertical direction when mounting and dismountingthe optical connector support block 1.

Underneath the optical connector support block 1, a polishing block 2comprising a polishing disk or grind wheel 7 is mounted on the base 31.The optical connector end face 5 which projects from the bottom surfacela of the block 1, is held in contact with the polishing surface of thegrind wheel 7 for desired inclined convex spherical surface polishing. Asecond drive system 60 provided inside the base 31 is coupled to thegrind wheel 7 to drive the grind wheel 7 by rotational driving and alsoexcentric driving, that is, cause rotation and revolution of the grindwheel 7.

As is seen from FIG. 5, in the polishing machine using the column typebase, the main shaft 32 is supported such that it extends vertically,and also the first drive system 33, optical connector support block 1,and polishing block including the grind wheel 7 and second drive system60 are all arranged in the vertical arrangement. Thus, loads applied tothe optical connector support and polishing blocks 1 and 2 substantiallyconsist of vertical components. The support structure is thus lesssubject to deformation. It is thus possible to hold the opticalconnector in the designed inclined attitude at all times to permitprecise inclined convex spherical surface polishing. In addition, sinceall the components including the main shaft 32 and optical connectorsupport block 1 are made of materials excellent in the mechanicalstrength, the overall structure has excellent rigidity. Thus, lesserrors are liable to result, the machining accuracy can be increased,and the excentricity of the radius of curvature of the convex sphericalsurface can be suppressed to be extremely small.

FIG. 6 is a schematic view showing the detailed internal structure ofthe optical connector support block 1. The block 1 basically has adisk-like double-wall structure comprising an inner disk-like member 35and an outer ring-like member 36, these members being made from thickmetal materials. The inner and outer members 35 and 36 are coupled toeach other via a bearing 61 for relative rotation. However, they aresecured to each other in the thrust direction. A land member 37 issecured to the upper surface of the ring-like member 36. A cup 39 ismounted on a lower end portion of the quill 38 of the main shaft 32. Theland member 37 is detachably inserted along the gap formed between thecup 39 and the outer periphery of the quill 38. The land member 37,quill 38 and cup 39 are secured to one another by a ball 40. The outerring-like member 36 thus is secured to the quill 38 and is capable ofbeing fed in the vertical direction. The inner disk-like member 35, onthe other hand, is coupled by a pin 41 provided in its upper surface tothe lower end surface of the shaft member 42 which is inserted in thequill 38. The inner disk-like member 35 thus is capable or rotation inunison with the shaft member 42 in both directions.

The plurality of rotary members 8, as noted above, are mounted in thesecured outer ring-like member 36 along the circumference thereof. Therotary members 8 are each rotatably mounted via a bearing (not shown) inthe outer ring-like member 36. The holding member 11 is assembled ineach rotary member 8, and the optical connector 3 can be held in aninclined attitude in the holding member 11. The holding member 11 iscapable of position adjustment by being advanced and retreated in theoptical axis direction of the optical connector 3 as noted above. Theouter periphery of a portion of the rotary member 8 that projects fromthe lower surface of the outer ring-like member 36 is frictionallycoupled to the edge of a disk 43 which extends radially outward from theinner disk-like member 35. With this frictional rotation drivemechanism, rotation of the disk 43 in unison with the inner disk-likemember 35 in both directions, causes reciprocal rotational driving ofthe rotary member 8. The rotary member 8 need not be driven byreciprocal rotational driving. Sometimes, it may be for being driven forrotation in a fixed direction.

FIG. 9 is a schematic view showing a second embodiment of the opticalconnector end face polishing apparatus according to the invention. Thisembodiment, unlike the preceding first embodiment, has a horizontalstructure with a polishing member disposed vertically. This apparatuscomprises an optical connector support section 201 for rotatablysupporting an optical connector 203 and a polishing disk 202 to be incontact with the end face 205 of the optical connector 203 for inclinedconvex spherical surface polishing. The optical connector supportsection 201 includes a rotary member 208, which is driven by a shaft 209for rotation about a horizontal axis 210 of rotation, and a holdingmember 211 mounted in the rotary member 208. The holding member 211 canhold the optical connector 203 such that the optical axis 212 of theoptical connector 203 is at a predetermined angle 8 to the axis 210 ofrotation. An adjusting mechanism 215 is provided between the holdingmember 211 and rotary member 208. The optical connector 203 is securedin position in a state that the optical axis point P on the opticalconnector end face 205 coincides with the axis 210 of rotation. In thisembodiment, the adjusting mechanism 215 has an X and a Y table 213 and214. It can adjust the holding member 211 along a plane perpendicular tothe axis 210 of rotation. That is, it can effect parallel movementadjustment of the optical connector 203 in a direction perpendicular tothe axis 210 of rotation while holding the inclined attitude of theoptical connector.

The operation of the apparatus shown in FIG. 9 will now be described.First, the optical connector 203 is set in the holding member 211, whichis then mounted on the surface of the Y table 214. Then, the polishingdisk 202 is retreated in a direction perpendicular to the axis 210 ofrotation, and a microscope 216 is brought to a position such that itfaces the holding member 211. At this time, the microscope 216 is setsuch that its optical axis coincides with the axis 210 of rotation.Then, the X and Y tables 213 and 214 are operated while observing theoptical connector end face 205 with the microscope 216 for positioningthe optical connector 203 such that the optical axis point P coincideswith the axis 210 of rotation. Subsequently, the polishing disk 202 isbrought in a direction 217 perpendicular to the axis 210 of rotation andmoved in a direction 218 of the axis 210 of rotation so that it isbrought into forced contact with the optical connector end face 205. Atthe same time, the rotary member 208 is driven by the shaft 209 forrotation to perform desired inclined convex spherical surface polishing.

As has been described in the foregoing, according to the invention theoptical connector is set in the holding member such that its opticalaxis is at a predetermined angle to a predetermined axis of rotation,and then it is positioned by moving it until the optical axis point atits end face coincides with the axis of rotation. In this state, theoptical connector is caused to undergo oscillating rotation about theaxis of rotation while its inclined end face is held in forced contactwith the polishing member for inclined convex spherical surfacepolishing. Thus, the apex of the inclined convex spherical surface andthe optical axis point of the optical connector coincide with eachother, and it is thus possible to suppress the excentricity of theradius of curvature of the convex spherical surface to an extremelysmall value. It is thus possible to realize reduction of reflectedreturn light while maintaining very low insertion loss. The opticalconnector manufactured according to the invention thus is subject to lownoise and suitably applicable to CATV or image transmission channeljumper cables.

What is claimed is:
 1. An apparatus for polishing optical connectors,comprising:an optical connector support section including:a holdingmember for holding an optical connector mounted therein, said opticalconnector having an optical axis; and a rotary member which is rotatableabout a predetermined axis of rotation; said holding member beingmounted in said rotary member such that optical axis of said opticalconnector is at a predetermined angle of inclination to said axis ofrotation of said rotary member; a polishing member section arranged tocontact with an end face of said optical connector which is mounted insaid holding member, for polishing said end face of said opticalconnector to a predetermined shape; first drive means for rotating saidrotary member of said optical connector support section to therebyrotate the inclined optical connector around said predetermined axis ofrotation; and second drive means for rotating said polishing membersection to cause said polishing member section to move relative to saidend face of said optical connector.
 2. The apparatus according to claim1, which further comprises adjusting means for adjusting a position ofsecurement of said optical connector relative to said rotary member,such that a point of said optical axis of said optical connector in saidend face of said optical connector coincides with said predeterminedaxis of rotation of said rotary member.
 3. The apparatus according toclaim 2, wherein said adjusting means includes thread means for causingadvancement and retreat of said holding member in an optical axisdirection.
 4. The apparatus according to claim 2, wherein said adjustingmeans comprises thread means for causing movement of said holding memberin a plane at right angles to said predetermined axis of rotation ofsaid rotary member.
 5. The apparatus according to claim 1, wherein saidpredetermined angle of inclination of said optical axis of said opticalconnector is 8° to 12°.
 6. The apparatus according to claim 1, whereinsaid polishing member section includes an elastic polishing memberarranged to contact said end face of said optical connector.